Yes and No.
You can buy memory online from a wide selection of memory sellers or stores who will be more than happy to sell you memory for cheap prices and offer you a lifetime warranty on the memory upgrade and give you support if you need it, but RAM is a physical product that you insert into your desktop or notebook computer to enhance speed and performance of your computer, regardless of make.
What you cannot do is add memory online as if RAM or memory were some kind of software or other free download. You can buy memory but it has to be shipped to you just as you would order a book from Amazon or Flowers for Delivery you buy the memory, wait for it to arrive and then follow instructions on how to install memory for your desktop or notebook computer.
Where To Buy Computer Memory
I have created a list of trusted and respected memory stores that I can recommend that will be happy to sell you a memory upgrade, and except for rare instances the memory upgrade you buy from these online memory stores will be much cheaper than if you were to buy memory from the manufacturer of your computer. It’s quite easy and possible to save up to half price on memory without much trouble at all by visiting the memory stores and and noting the lowest price from each memory reseller or manufacturer.
If this sounds like a heck of a lot of work to go to each memory store and check the price for you notebook (desktops seem to be less popular these days) it is, but I have taken the opportunity to do the work for you and offer ram prices compared from a list of respectable memory stores that offer the best ram prices as well as the customer support you would expect and deserve.
RAM Memory is cheap. Especially if you buy RAM or Memory online and have it shipped to you where you can install it yourself with nothing more than some household tools you already have. But you have to buy the memory first.